Trapping of normal EB1 ligands in aggresomes formed by an EB1 deletion mutant
<p>Abstract</p> <p>Background</p> <p>EB1 is a microtubule tip-associated protein that interacts with the APC tumour suppressor protein and the p150glued subunit of dynactin. We previously reported that an EB1 deletion mutant that retains both of these interactions but d...
| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
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BMC
2005-04-01
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| Series: | BMC Cell Biology |
| Online Access: | http://www.biomedcentral.com/1471-2121/6/17 |
| _version_ | 1818806934644457472 |
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| author | Askham Jon M Adams Matthew Lee Tracy Milward Kelly Riess Nick P Morrison Ewan E |
| author_facet | Askham Jon M Adams Matthew Lee Tracy Milward Kelly Riess Nick P Morrison Ewan E |
| author_sort | Askham Jon M |
| collection | DOAJ |
| description | <p>Abstract</p> <p>Background</p> <p>EB1 is a microtubule tip-associated protein that interacts with the APC tumour suppressor protein and the p150glued subunit of dynactin. We previously reported that an EB1 deletion mutant that retains both of these interactions but does not directly associate with microtubules (EB1-ΔN2-GFP) spontaneously formed perinuclear aggregates when expressed in COS-7 cells.</p> <p>Results</p> <p>In the present study live imaging indicated that EB1-ΔN2-GFP aggregates underwent dynamic microtubule-dependent changes in morphology and appeared to be internally cohesive. EB1-ΔN2-GFP aggregates were phase-dense structures that displayed microtubule-dependent accumulation around the centrosome, were immunoreactive for both the 20s subunit of the proteasome and ubiquitin, and induced the collapse of the vimentin cytoskeleton. Fractionation studies revealed that a proportion of EB1-ΔN2-GFP was detergent-insoluble and ubiquitylated, indicating that EB1-ΔN2-GFP aggregates are aggresomes. Immunostaining also revealed that APC and p150glued were present in EB1-ΔN2-GFP aggregates, whereas EB3 was not. Furthermore, evidence for p150glued degradation was found in the insoluble fraction of EB1-ΔN2-GFP transfected cultures.</p> <p>Conclusion</p> <p>Our data indicate that aggresomes can be internally cohesive and may not represent a simple "aggregate of aggregates" assembled around the centrosome. Our observations also indicate that a partially misfolded protein may retain the ability to interact with its normal physiological ligands, leading to their co-assembly into aggresomes. This supports the idea that the trapping and degradation of co-aggregated proteins might contribute to human pathologies characterised by aggresome formation.</p> |
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| format | Article |
| id | doaj.art-0b77dea1629645ea92940ca1c9a261cc |
| institution | Directory Open Access Journal |
| issn | 1471-2121 |
| language | English |
| last_indexed | 2024-12-18T19:17:40Z |
| publishDate | 2005-04-01 |
| publisher | BMC |
| record_format | Article |
| series | BMC Cell Biology |
| spelling | doaj.art-0b77dea1629645ea92940ca1c9a261cc2022-12-21T20:56:06ZengBMCBMC Cell Biology1471-21212005-04-01611710.1186/1471-2121-6-17Trapping of normal EB1 ligands in aggresomes formed by an EB1 deletion mutantAskham Jon MAdams MatthewLee TracyMilward KellyRiess Nick PMorrison Ewan E<p>Abstract</p> <p>Background</p> <p>EB1 is a microtubule tip-associated protein that interacts with the APC tumour suppressor protein and the p150glued subunit of dynactin. We previously reported that an EB1 deletion mutant that retains both of these interactions but does not directly associate with microtubules (EB1-ΔN2-GFP) spontaneously formed perinuclear aggregates when expressed in COS-7 cells.</p> <p>Results</p> <p>In the present study live imaging indicated that EB1-ΔN2-GFP aggregates underwent dynamic microtubule-dependent changes in morphology and appeared to be internally cohesive. EB1-ΔN2-GFP aggregates were phase-dense structures that displayed microtubule-dependent accumulation around the centrosome, were immunoreactive for both the 20s subunit of the proteasome and ubiquitin, and induced the collapse of the vimentin cytoskeleton. Fractionation studies revealed that a proportion of EB1-ΔN2-GFP was detergent-insoluble and ubiquitylated, indicating that EB1-ΔN2-GFP aggregates are aggresomes. Immunostaining also revealed that APC and p150glued were present in EB1-ΔN2-GFP aggregates, whereas EB3 was not. Furthermore, evidence for p150glued degradation was found in the insoluble fraction of EB1-ΔN2-GFP transfected cultures.</p> <p>Conclusion</p> <p>Our data indicate that aggresomes can be internally cohesive and may not represent a simple "aggregate of aggregates" assembled around the centrosome. Our observations also indicate that a partially misfolded protein may retain the ability to interact with its normal physiological ligands, leading to their co-assembly into aggresomes. This supports the idea that the trapping and degradation of co-aggregated proteins might contribute to human pathologies characterised by aggresome formation.</p>http://www.biomedcentral.com/1471-2121/6/17 |
| spellingShingle | Askham Jon M Adams Matthew Lee Tracy Milward Kelly Riess Nick P Morrison Ewan E Trapping of normal EB1 ligands in aggresomes formed by an EB1 deletion mutant BMC Cell Biology |
| title | Trapping of normal EB1 ligands in aggresomes formed by an EB1 deletion mutant |
| title_full | Trapping of normal EB1 ligands in aggresomes formed by an EB1 deletion mutant |
| title_fullStr | Trapping of normal EB1 ligands in aggresomes formed by an EB1 deletion mutant |
| title_full_unstemmed | Trapping of normal EB1 ligands in aggresomes formed by an EB1 deletion mutant |
| title_short | Trapping of normal EB1 ligands in aggresomes formed by an EB1 deletion mutant |
| title_sort | trapping of normal eb1 ligands in aggresomes formed by an eb1 deletion mutant |
| url | http://www.biomedcentral.com/1471-2121/6/17 |
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